Multiple semiconductor substrates are typically stored and transported together in batches by a wafer carrier throughout a semiconductor fabrication facility (also called as “fab”) between the loadports of different wafer processing tools or equipment. Such tools generally perform various photolithography, etching, material/film deposition, curing, annealing, inspection, or other processes used in IC chip manufacturing. One such wafer carrier is a front opening unified pod (FOUP) which is a plastic enclosure designed to hold a plurality of wafers ranging from 300 mm to 450 mm sizes in a controlled environment. Typically, each wafer carrier holds approximately 25 wafers. The individual wafers are stacked vertically in the FOUP and stored in a wafer support frame having multiple separate wafer shelves or slots.